Hard Drive Power Switch Module for 2.5 inch/3.5 inch SATA HDD/SSD, with TVS protection. SATA Switch, HDD Power Switch Hard Drive Selector，Controls up to Four HDDs, Intelligent Control Hard Disk Manage

if you have something like the hpc 820 which uses these sleds here to get your hard drives in and out and it already has the SATA power connection inside and you just slide them in but of course works fine for three and a half inch drives in the three and a half inch drives fit fine in in in these two lists trays but whenever you want to use something like an SSD that's two and a half inch or even just a two and a half inch hard drive you can't put that directly in the sled it just won't won't connect so you need some sort of adapter now technically you could just take this and stick it in there it will actually stay because these are so light but that's not really a good idea what you need is an adapter so you can buy the HP branded one if you want to spend you know 30 40 50 bucks or you can get something from Roswell Rosewill the two and a half inch to three and a half inch SATA hard